Aprilaire 51 Current Sensing Relay 120V

The Aprilaire 51 current sensing relay is used to turn any humidifier on when the indoor blower of the air handler is energized. The relay makes installing any humidifier easier than ever before. This part is designed to be installed in series with a 120 volt circuit. Installation instructions included. This relay has a trip on point of 4 amps so if it sees less than 4 amps it will not turn on, if it sees 4 amps or more it will turn on. If you have a load LESS than 4 amps and you still want to use this relay you will need to wrap the wire you are sensing through the metal loop several times. Each time you wrap it through the loop it will add that amperage up. For instance if you have a 2 amp load and you wrap it through 3 times it will see 6 amps and turn on.